Question

Моторная лодка прошла по течению реки 10 км против течения 15 км затратив на весь путь 1 час 10 минут Найдите скорость лодки по течению если скорость течения реки равна 2 км ч

Answer 1

Calculation of the Boat's Speed in Still Water

To find the speed of the boat in still water, we can use the formula:

Speed of boat in still water = (Distance traveled)/(Time taken)

In this case, the boat traveled a distance of 10 km against the current and took 1 hour and 10 minutes (or 1.17 hours) to complete the entire journey.

Let's calculate the speed of the boat in still water:

Speed of boat in still water = 10 km / 1.17 hours

The speed of the boat in still water is approximately 8.55 km/h.

Calculation of the Speed of the River Current

To calculate the speed of the river current, we can use the formula:

Speed of river current = (Distance traveled)/(Time taken)

In this case, the boat traveled a distance of 15 km with the current and took 1 hour and 10 minutes (or 1.17 hours) to complete the entire journey.

Let's calculate the speed of the river current:

Speed of river current = 15 km / 1.17 hours

The speed of the river current is approximately 12.82 km/h.

Calculation of the Speed of the Boat in the River Current

To calculate the speed of the boat in the river current, we can use the formula:

Speed of boat in river current = Speed of boat in still water - Speed of river current

Using the values we calculated earlier:

Speed of boat in river current = 8.55 km/h - 12.82 km/h

The speed of the boat in the river current is approximately -4.27 km/h.

Note: The negative sign indicates that the boat is moving against the current.

Therefore, the speed of the boat in the river current is approximately 4.27 km/h.